Benzothiazolinylidene substituted ureas

ABSTRACT

Novel ureas and thioureas of the formula WHERE X is oxygen or sulfur, R1 and R2 are alkyl radicals of not more than four carbon atoms, R3 is alkyl of not more than 12 carbon atoms, alkenyl of not more than 12 carbon atoms, cycloalkenyl of six through eight carbon atoms, haloalkyl of not more than 12 carbon atoms and with not more than three halogen atoms therein on the one and two carbon atoms, halophenyl of not more than five halogen atoms, haloalkylphenyl of not more than three haloalkyls having not more than four carbon atoms and not more than three halogen atoms therein, with the provision that the double bond in said alkenyl and cycloalkenyl are not in the 1-position. These compounds are useful as herbicides.   D R A W I N G

I United States Patent 1191 Dixon Apr. 30, 1974 BENZOTHIAZOLINYLIDENE SUBSTITUTED UREAS [75] inventor: William D. Dixon, Kirkwood, Mo.

[73] Assignee: Monsanto Company, St. Louis, Mo.

[22] Filed: Mar. 20, 1972 21 Appl. No.2 236,166

Related US. Application Data [62] Division of Ser. No. 97,054, Dec. 10, i970, Pat. No.

Primary Examiner-Lewis-Gotts Assistant Is'xamirter-Catherine L. Mills Attorney, Agent, or Firm-John L. Young; Paul C. Krizov; Neal E. Willis [57] ABSTRACT Novel ureas and thioureas of the formula where X is oxygen or sulfur, R and R are alkyl radicals of not more than four carbon atoms, R is alkyl of not more than 12 carbon atoms, alkenyl of not more than 12 carbon atoms, cycloalkenyl of six through eight carbon atoms, haloalkyl of not more than 12 carbon atoms and with not more than three halogen atoms therein on the one and twocarbon atoms, halophenyl of not more than five halogen atoms, haloalkyL' phenyl of not more than three haloalkyls having not more than four carbon atoms and not more than three halogen atoms therein, with the provision that the double bond in said alkenyl and cycloalkenyl are not in the l-position.

These compounds are useful as herbicides.

15 Claims, N0 Drawings BENZOTHIAZOLINYLIDENE SUBSTITUTED UREAS where X is oxygen or sulfur, R and R are alkyl radicals of not more than four carbon atoms, R is alkyl of not more than 12 carbon atoms, alkenyl of not more than 12 carbon atoms, cycloalkenyl of six through eight car bon atoms, haloalkyl of not more than 12 carbon atoms and with not more than three halogen atoms therein on the l (or a) and 2 (or B) carbon atoms, halophenyl of not more than 5 halogen atoms, haloalkylphenyl of not more than three haloalkyls having not more than four carbon atoms and not more than three halogen atoms therein, with the proviso that the double bond in said alkenyl and cycloalkenyl are not in the 1-position.

Preferred compounds of this invention are those wherein X is sulfur or wherein R is alkyl or alkenyl and wherein X is sulfur and R is alkyl simultaneously. Other preferred embodiments are halophenyl radicals which have a maximum of three halogens on the phenyl ring.

The alkyl radicals represented by R and R can be straight or branched, primary, secondary or tertiary. For example, R, and R; can each be methyl, ethyl, propyl, isopropyl, n-butyl, sec.butyl and tert.butyl.

The alkyl radicals represented by R can likewise be straight or branched, primary, secondary or tertiary. Examples are methyl, propyl, isopropyl, n-butyl, sec.- butyl, isobutyl and tert.butyl, n-hexyl, isononyl, ndodecyl and isododecyl.

Examples of alkenyl radicals represented by R are 2-propenyl, 2-butenyl, 2-isobutenyl, .2-hexenyl, '3- nonenyl, 2-dodecenyl.

Examples of cycloalkenyl radicals represented by R are 2-cyclohexenyl, 3-cyclohexenyl and 2- cyclooctenyl.

Examples of haloalkyl radicals represented by R are chloromethyl; trifluoromethyl; 2-bromoethyl; iodomethyl and 2,2,2,-trifluoromethyl.

Examples of halophenyl radicals represented by R are 2-chlorophenyl; 2-fluorophenyl; 4-bromopheny]; 2-iodophenyl; 2,4-difluorophenyl and 2,4,6- trichlorophenyl.

Examples of haloalkylphenyl radicals represented by R are 2-trifluoromethylphenyl; 4-bromomethylphenyl; 4-iodomethylphenyl; 3-chloromethylphenyl and 3,5- di(trifluoromethyl)phenyl.

Illustrative examples of the compounds of this invention are:

l-( 3 ,6-dimethyl-2-benzothiazolinylidene)-3- methylurea l-(3-meth yl, 6-tert.butyl-2-benzothiazolinylidene)-3- methylurea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3- isododecylurea l-(3,6-dimethyl-2-benzothiazolinylidene)-3-(2- isobutenyl)urea 1-(3,6-dimethyl-2-benzothiazolinylidene)-3-(2- dodecenyD-urea 1-(3,6-dimethyl-Z-benzothiazolinylidene)-3-( 2- cyclohexenyl)urea 1-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3- trifluoromethylurea 1-( 3 ,6-dimethyl-Z-benzothiazolinylidene)-3-( 2- fluorophenyl)urea 1-(3,6-dimethyl-2-benzothiazolinylidene)-3-(2,4-

dibromophenyl)urea 1-(3,6-dimethyl-2-benzothiazolinylidene)-3-(3- chloromethylphenyl)urea l-( 3 ,6-dimethyl-Z-benzothiazolinylidene )-3-methyl- 2-thiourea l-( 3 -methyl,6-tert.butyl-2-benzothiazolinylidene )-3- methyl-2-thiourea l-(3,6-dimethyl-2-benzothiazolinylidene)-3isopropyl-2-thiourea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-isododecyl-2-thiourea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2- isobutenyl)-2-thiourea 1-(3,6-dimethyl-2-benzothiazolinylidene)-3-(2- cyclohexenyl)-2-thiourea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3- chloromethyl-urea l-( 3 ,6-dimethyl-2-benzothiazolinylidene)-3-( 2,2,2-

trifluoroethyl)urea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2- fluorophenyl)-2-thiourea 1-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2,4-

dibromophenyl-2-thiourea The compounds of this invention in general can be prepared by reacting the 3,6-dialkyl-2- benzothiazolinylimine with the isocyanate or isothiocyanate corresponding to the structure desired as product although the iodoalkyl containing compounds are more suitably prepared by preparation of a corresponding different haloalkyl and then displacing the halo thereof with Nal in acetone at room temperature (i.e., about 20C) and pressure (i.e. about 15 psi.). The reaction will-be made clear by the following detailed examples.

EXAMPLE I About 0.05 mole or 8.7 g. of 3,6-dimethyl-2- benzothiazolinylimine was dissolved in about 50 ml. of ether and was placed in a four-necked flask equipped with a thermometer, stirrer, condenser (using tap water) and a dropping funnel. About 0.05 mole or 3.7 g. of methylisothiocyanate was added dropwise to the solution in the flask. The reaction was noted to be slightly exothermic. The mixture was allowed to stand overnight and filtered. The yellow needles were recrystallized from about 300 ml. of acetonitrile and dried at about C at 0.3 mm. Hg. An off-white powder melting at 205.5207.5 C was obtained. Elemental analysis was as follows: a

Nuclear magnetic resonance (NMR) spectral analysis confirmed the product 1-( 3 ,6-dimethyl-2- benzothiazolinylidene)-3-methyl-2-thiourea.

EXAMPLE 11 Using similar equipment as that in Example 1, 0.05 mole or 8.7 g. of 3,6-dimethyl-2-benzothiazolinylimine was dissolved in about 150 ml. of ether and placed in the flask. About 0.5 mole or 9.4 g. of 3,4-

dichlorophenylisocyanate dissolved in about 60 ml. of ether was added dropwise to the flask. The reaction was exothermic and solid product formed immediately. The solid was filtered and recrystallized from dimethylformamide. Recrystallized product dried at about 15 100C at 0.3 mm. Hg. had a melting point of 216218C. Elemental analysis was as follows:

C H CI N OS %C %H %N Calculated: 52.47 3.58 11.47 Found: 5253 3.62 11.61

NMR spectral analysis confirmed the expected product 2 half inch from the top of each pan. A pro-determined number of seeds of the test plant species are placed on top of the soil in the pans. The seeds are covered with a three-eighths inch layer of soil and the pan leveled. The active ingredient is applied by spraying it on the surface of the soil as a herbicidal formulation contain: ing a sufficient amount of active ingredient to obtain the desired rate of active ingredient per acre.

The seed-containing pans are placed on a sand bench .and maintained under ordinary conditions of sunlight and watering. The plants are observed at the end of approximately 14 days and the results recorded. The herbicidal activity index is based on the average percent control of each seed lot. The herbicidal activity index is converted to a relative numerical scale for the sake of brevity and simplicity in the table.

The pre-emergent herbicidal activity index used is defined as follows:

Average Percent Numerical Control Scale 0 to 0 26 to 50 l 51 to 75 2 76 to 100 3 In Table 1, below, the dosage rate, the spectrum of plant seeds treated, and the results of tests carried out according to the above procedure are indicated for several of the compounds of this invention.

7 TABLE 1 Com Dosage Canada Cockle- Velvet Morning Lambs- Smart- Nuts Ouack- Johnson Downy Barnyard pound Lb/Acre Thistle bur Leaf Glory quarter weed edge grass Grass Brome Grass A 5 0 0 0 2 0 0 2 l l 0 0 l3 5 l O O O O O l O l 0 2 C 5 0 0 0 0 2 3 0 0 0 l 0 cidal is used to identify the overall as well as the selective control activity of the compositions of this invention.

The term plant as used herein and in the appended claims is inclusive of dormant seeds, gerrninant seeds,

germinative seeds, emerging seedlings and established woody and herbaceous vegetation including the roots and above-ground portions.

The term control as used herein and in the appended claims is inclusive of the actions of (1) killing,

(2) inhibiting growth, reproduction or proliferation,

and (3) removing, destroying or otherwise diminishing the occurrence and activity of plants and is applicable to any of the stated actions, or any combination thereof.

The term herbicidal formulation or composition as used herein means at least one compound of this invention in combination with an adjuvant.

EXAMPLE 111 The pre-emergent herbicidal activity of the active ingredients of this invention is demonstrated as follows: A good grade of top soil is placed in aluminum pans and compacted to a depth of three-eighths inch to one- A l-(3,6-dimethyl-2-benzothiazolinylidene)-3-methyl-2-thiourea B 1-(3,4-dichlorophenyl)-3-(3,6-dimethyl-2- benzothiazolinylidene)-urea C 1-methyl-3-(3,6-dimethyl-2- benzothiazolinylidene)urea The active ingredients hereindefined are suitable for both pre-emergent and post-emergent plant application. That is, they are effective in controlling the growth of germinant seeds, emerging seedlings and established vegetation by exposing the seeds, emerging seedlings, or the roots or above-ground portions to the action of an effective amount of one or more of these herbicidally active compounds; however, the best results are usually obtained in a pre-emergent application. Such constitutes a preferred embodiment of the utility of these compounds.

In foliar treatment for the modification of vegetative growth, the active ingredients are applied in amounts from about 0.1 to about 50 or more pounds per acre, preferably about 0.1 to 15 pounds per acre in foliar treatments. In soil applications, it is desirable that the active ingredients be distributed to a depth of at least 0.2 inches. In pre-emergence herbicidal applications the active ingredients are usually applied in amounts from about 0.1 to 25 pounds per acre but preferably from about 0.1 to 10 pounds per acre. It is believed that one skilled in the art can readily determine from the teachings of this specification, including examples, the procedure for any particular desired application.

In using the compounds of this invention, the active ingredients can be used alone or in combination with a material referred to in the art as an adjuvant in liquid or solid form. The usual purpose of adjuvants is to facilitate application of the herbicidal composition and to obtain the desired dosage rate. Herbicidal formulations are prepared by admixing the active ingredient with one or more adjuvant which includes diluents, exten-' ders, carriers and conditioning agents to provide compositions in the form of finely divided particulate solids, granules, pellets, solutions, dispersions or emulsions. Thus, the active ingredient can be used with an adjuvant such as a finely-divided particulate solid, a liquid of organic origin, water, a wetting agent, dispersing agent, an emulsifying agent or any suitable combination of these.

Suitable adjuvants of the foregoing types are not here defined in detail as to composition, particle size, relative amounts etc. since they are well known in the art.

In general, the active ingredients may be formulated with the active ingredient in minor or major proportions in accordance with the table below:

Concentration of Type of Formulation Active Ingredient l. Granules of relatively large particle size 5 to 50% 2. Powdery dusts 2 to 90% 3. Wettable powders 2 to 90% 4. Emulsifiable concentrates 5 to 95% 5. Solutions .01 to 95% 6. One of the less common types of formulations depending on the desired mode of application .0l to 95% embraced by the appended claims in their broadest construction.

What is claimed is:

I. Herbicidal method which comprises applying to plants an adjuvant and a herbicidally effective amount of at least one compound of the formula where X is oxygen or sulfur, R and R are alkyl radicals of not more than 4 carbon atoms, R, is alkyl of not more than 12 carbon atoms, alkenyl of not more than 12 carbon atoms, cycloalkenyl of six through eight carbon atoms, haloalkyl of not more than 12 carbon atoms and with not more than three halogen atoms therein on the one and two carbon atoms, halophenyl of not more than five halogen atoms, haloalkylphenyl of not more than three haloalkyls having not more than 4 carbon atoms and not more than three halogen atoms therein, with the proviso that the double bond in said alkenyl and cycloalkenyl are not in the l-position.

2. A method of claim I wherein X is sulfur.

3. A method of claim 1 wherein X is oxygen.

4. A method of claim 1 wherein R is alkyl.

5. A method of claim 1 wherein R is alkenyl.

6. A method of claim 1 wherein R is halophenyl with up to three halogens therein.

7. A method of claim 2 wherein R is alkenyl.

8. A method of claim 2 wherein R is cycloalkenyl.

9. A method of claim 2 wherein R is halophenyl. 10. A method of claim 3 wherein R is alkenyl. 11. A method of claim 3 wherein R is cycloalkenyl.

12. A method of claim 3 wherein R is halophenyl.

13. A method of claim I wherein the compound is l (3,6-dimethyl-2-benzothiazolinylidene)-3-methyl-2- thiourea.

I4. A method of claim 1 wherein the compound is l- (3,4-dichlorophenyl)-3-(3,6-dimethyl-2- benzothiazolinylidene)-urea.

15. A method of claim 1 wherein the compound is lmethyl-3-( 3,6-dimethyl-2-benzothiazolinylidene)urea. 

2. A method of claim 1 wherein X is sulfur.
 3. A method of claim 1 wherein X is oxygen.
 4. A method of claim 1 wherein R3 is alkyl.
 5. A method of claim 1 wherein R3 is alkenyl.
 6. A method of claim 1 wherein R3 is halophenyl with up to three halogens therein.
 7. A method of claim 2 wherein R3 is alkenyl.
 8. A method of claim 2 wherein R3 is cycloalkenyl.
 9. A method of claim 2 wherein R3 is halophenyl.
 10. A method of claim 3 wherein R3 is alkenyl.
 11. A method of claim 3 wherein R3 is cycloalkenyl.
 12. A method of claim 3 wherein R3 is halophenyl.
 13. A method of claim 1 wherein the compound is 1-(3,6-dimethyl-2-benzothiazolinylidene)-3-methyl-2-thiourea.
 14. A method of claim 1 wherein the compound is 1-(3,4-dichlorophenyl)-3-(3,6-dimethyl-2-benzothiazolinylidene)-urea.
 15. A method of claim 1 wherein the compound is 1-methyl-3-(3,6-dimethyl-2-benzothiazolinylidene)urea. 